Answer:
Plant cells use more than one pigment because more than one pigment or multiple pigments absorb different wavelength of light from sun and this difference absorption spectra is very much important during photosynthesis.
Step-by-step explanation:
Plant cells use multiple pigments because some pigments also called principle pigments function within the reaction center where some accessory pigments are also present such as carotene,phycobillin, xanthophyll which act as antena complex that play an important in light absorption.
The presence of different pigment provides different coloration of fruits,leaves.For example presence of carotene gives orange,yellow coloration to carrot,tomato.